Steering propeller



y Oct- 3, 1961 SVEN AKE JRDMO 3,002,486

STEERING PROPELLER Filed Nov. 25, 1958 2 Sheets-Sheet 1 HIS ATTO RN EYS Ot- 3, 1951 svEN AKE JRDMo 3,002,485

STEERING PROPELLER 2 Sheets-Shea?I 2 Filed NOV. 25, 1958 INVENTOR SVEN AKE JARDMO BY H IS ATTORNEYS 3,002,486 STEERING PROPELLER Sven lie `lrdmo, Karlstad, Sweden, assignor to Aktiebolaget Karlstads Mekaniska Werkstad, Karlstad, Sweden, a company of Sweden Filed Nov. 25, 1958, Ser. No. 776,294 Claims priority, application Sweden Nov. 30, 1957 3 Claims. (Cl. 114-148) The present invention relates to steering mechanisms for ships and other vessels and it relates more partcularly to an improvement in steering mechanisms of the type including a screw propeller which is located in a tunnel extending athwart the hull of a ship.

Prior steering mechanisms of the kindV referred to above have not been very satisfactory because the steering effect was diiiicult to control in magnitude and direction and, in particular, such systems are difficult to service and repair unless the ship containing the mechanism is placed in dry dock.

In accordance with the present invention, a steering system is provided in which the propeller blades are adjustably attached to a hub to enable their pitch to be varied from zero to a maximum and to be reversed by means of a hydraulic motor arranged in the hub of the propeller. The provision of a hydraulic control for changing the pitch of the propeller blades provides substantial advantages in manoeuvering the ship and also enables the mechanism for driving the propeller to be simpliiied, inasmuch as a motor having a low starting torque and without speed controls therefor, such as an asynchronous electric motor can be used'.

The invention also includes an improved mounting structure for the propeller which enables the entire propeller structure and the controls therein to beremoved for overhaul without putting the ship in drydock.

For a better understanding of the invention reference may be had to the accompanying drawings in which:

FIG. 1 is a horizontal cross-sectional view of the bow of a ship equipped with a steering device embodying the invention;

FIG. 2 is an elevational view of the steering device, with the hull structure of the ship omitted;

FIG. 3 is a circuit diagram of the control system for the steering device, and

FIG. 4 is a cross-sectional View on an enlarged scale of the hub and supporting structure for the propeller of FIG. 1.

As shown in FIG. 1, athwart of the bow B of the ship is a horizontal tunnel 11 of approximately uniform width, which is located in its entirety below the low load mark of the ship. Inserted in the middle part of said tunnel is a cylindrical drum 12 which is held against axial displacement by resilient rings 13, 14 inserted into grooves in a rigid part of the bow B of the ship. The rings 13, 14 are removable to enable the drum to be drawn out axially from the bow B to either side and hoisted up, so that the structural elements attached thereto and described in greater detail hereafter can be overhauled without docking the ship.

Arranged at about the center of said drum 12 and coaxial therewith is screw propeller 21 having four approximately sector-shaped propeller blades 22, the outer ends of which are Aclose to the wall of the drum 12. The number of blades can be varied, of course, for example, the propeller may have two, three or more than four blades. One end of a section 23 of a propeller shaft 24 (FIG. 4) on which the propeller 21 is mounted is journalled in two bearings 25, 26 which are carried by and enclosed within a casing 28. Four struts 29, 30, 31 and 32, which extend radially and at right angles to the shaft 24, support the casing 28. Another section 33 of ited States Patent ICC the propeller shaft 24 is journalled in a bearing 34 carried by and enclosed within a casing 35 which is supported by means of struts 36, 37 and 38. All of the struts are of a streamlined cross-section and may be mounted for rotation about their longitudinal axes to control the direction of the water flowing through the tunnel 11. Together with a rotary casing 39 forming apart of the propeller 21, the casings 28 and 35 form a cylindrical body having rounded ends located centrally in the tunnel 11 and which sets up a rather low flow resistance to the water driven by the propeller through the tunnel in one direction or the other.

Bolted to end flanges 40 and 40a at the inner ends of the propeller shaft sections 23 and 33, is a hub 41 in which the root ends of the propeller blades 22 are turnably attached in such a manner that their pitch can be changed. Control of the blades is afforded by a hydraulic cylinder 42 in the hub 41 coaxial with the propeller shaft portions 23, 33. A piston 43 movable axially in the cylinder 42 has a piston rod 44 which cooperates with a hub disc 4S bolted to the root of each of the propeller blades. An eccentric pin (not shown) on each hub disc 45 projects into a transverse groove 46 on the piston rod 44. The eccentric pin and groove structure may be the same as that shown in U.S. Patent No. 2,244,770.

vAttached to the propeller shaft portion 23 between the bearings 25 and 26 is a bevel gear 51 engaging a bevel pinion 53 attached to the end of a horizontal driving shaft 55. Shaft 55 extends horizontally and lengthwise of the ship within the strut 30 which is tubular and somewhat thicker than the other struts 29, 3.1 and 32 as shown in FIG. 2. The shaft 55 is coupled to the shaft of an electric motor 56 which may be of the asynchronous type or some other simple motor inasmuch as it is not required to have great starting torque, nor does it need to be controllable as to speed. In the connection between the shaft 55 and the motor 56 are two separate shaft pieces 57, 58 and three couplings 59, 60, 61. By dismantling the couplings 60, 61, the shaft piece 58 can be removed and then the shaft piece 57 and the coupling sleeve 59 can be Withdrawn outside of the wall of the drum 12 Where they do not interfere with withdrawal of the drum 12 from the tunnel 11.

Coupled to the shaft of the motor 56 is a pump 62 for pumping oil from a reservoir 63 through conduits 64, 65 within the strut 30 for circulation in the casing 28 to lubricate the gears 51, 53 and the bearings 25 and 27. Inserted in said conduits are coupling members 66,' 67 `facilitating their disconnection when removing the drum 12. The interior of the casing 28 is sealed to the propeller shaft by means of a stuing box 68.

The hydraulic cylinder 42 is arranged on the side of the propeller opposite to the gears 51, 53, and pressure Oil is supplied to said cylinder through the hollow strut 36. To this end said strut houses two conduits 69, 70 which, by means of a control valve 71, can be connected alternately to an outlet leading to an oil reservoir 72 (FIG. 3) and to the pressure side of the pump 73 driven by an electric motor 75. The lower ends of the conduits 69, 70 are flexible and communicate with grooves 76, 77 in the inner face of a sealing sleeve 78. By means of a shoulder 79 cooperating with a guide 81 attached to the casing 35, the sleeve 78 is guided in such a manner that it can move axially but is restrained against rotation. The sleeve 78 surrounds another sleeve 83 which is guided by means of pins projecting into holes 86 in the end of the propeller shaft and which is forced to take part in the rotation of the shaft. Two concentric tubes 87, S9 are attached at one of their ends to the piston 43 and open into the cylinder 42 on opposite sides of the piston. These tubes have their outer ends extending into the sleeves 83, 78 and are attached to the ysame s o that the sleeves move axially with the piston 43. Holes 90 in the sleeve 83 are located opposite to the grooves 77 of' the sleeve 78. The holes 90 connect the conduit 70 with the interior ofthetube 89. and therefore, with the lefthand end of the cylinder 41. Other holes 91 connect the conduitl 69 with the space between the tubes 87 and 89 and with the right-hand end ofthe, cylinder 42.

Attached to the end of the sleeve 7S is a Wire 92 which runs over a sheave 93 rotatably mounted in the casing 3S, through a guide tube 94 arranged in the strut 36 and is connected to a position indicator 95 (FIG. 3) which by means of remote control is connected to an indicating instrument 95a on the control switchboard97 located on the bridge of the ship. Also connected to said switchboard are electric circuits 98, 99 and 160 for starting the motors 56, 75 and for controlling the valve 71.

When the device described is not used, the propeller blades are set in theA vertical plane, Le., at zero pitch. When the device is to be used for steering manoeuvre, the motors 56and 75 are started. The motor 56 starts easily and accelerates to operating speed for the reason that the propeller blades are in neutral position. The motor 75 drives the pump 73, whereby liquid pressure is created for moving the piston 43. The device now stands ready for steering. If it is desired to turn the bow of the ship for instance to the starboard, the control valve 71 is actuated from the switch board 97 to supply liquid under pressure through the conduit 70, grooves 77, holes 99 and the tube 89 to the left-hand end ofthe cylinder 42 thereby forcing the piston 43 to the right. Liquid is discharged from the right-hand end of the cylinder 42 through tube 87, groove 76, and conduit 69 to the reservoir 72. The propeller blades are thereby adjusted and given such a pitch that the propeller drives Water through the tunnel 11 from the starboard side to the port side of the ship, causing the ship to swing to starboard due to reaction. The pitch of the propeller blade is indicated on the switch board by the wire 92 and the transmitting means connected thereto.

Steering the ship to port is accomplished in the same way, that is by actuating the valve 71 to supply hydraulic pressure to the right-hand end of the cylinder 42to force the piston 43 to the left thereby reversing the pitch of the propeller blades 22.

The steering effect can easily be varied as to its magnitude and direction `by adjusting the pitch of the propeller blades and without changing the speed ofthe propeller.

It will be understood that the above-describedy embodiment is an illustrative example of the application of the invention, and modifications in various respects can be made without departing from the scope ofthe invention as set forth in the following claims. v

I claim:

l. A steering mechanism for a ship comprisingl atunnel member extending athwart `the hull of the ship and having ends opening through opposite sides of said hull, a cylindrical drum tting slidably in said tunnel member, means releasably engaging said drum for retaining it against sliding in and removal from said tunnel member, groups of struts located adjacent and xed to opposite ends of said drum, a horizontal propeller shaft rotatably supported by and extending between said groups of struts, a variable and reversible pitch propeller mounted on said shaft between said groups-of struts, a hydraulic motor carried by said propeller shaft and connected to said propeller for varying and reversing its pitch, a drive shaft rotatably mounted in one of said struts,v means connecting said drive shaft tosaidipropeller, power means in said hull outside said tunnel member for driving said drive shaft, a releasable coupling between' said power means and said. drive shaft located approximately at the wall of said drum, conduits mounted in another strut and connected to said hydraulic motor, means in said hull outside saidtunnelmember to supply hydraulic uid to said conduits and discharge hydraulic fluid from said conduits to actuate said motor, and coupling members releasably connecting said conduits to said supply means, said'coupling and saidv coupling members being releasable to enable said drum to be removed from said tunnel member.

2. The mechanism defined in claim 2 in which said struts are ofstreamlined'cross section and are mounted'in said tunnel member for rotation around their longitudinal axes to`form guide vanes for the water owing through the tunnel member.

3. A steering mechanism for a ship comprising a tunnel member extending athwart the hull of the ship and having ends opening through opposite sides of said hull, a cylindrical drum fitting slidably in said tunnel member, ring members detachably mounted in said tunnel at the opposite ends of said drum and engaging said ends for retaining said drum against sliding in and removal from said tunnel member, groups of'struts located adjacent and fixed to opposite ends of said drum, a horizontal propeller shaft rotatably supported by and extending between said groups` of struts, a variable and reversible pitch propeller mounted on-said shaft between said groups of struts, a hydraulic motor carried by said propeller shaft and connected to said propeller for varying and reversing its pitch, a drive shaft rotatably mounted in one of said struts, means connecting said'drive shaft to said propeller, power means in said hull'outside said tunnel member for driving said drive shaft and'a releasable coupling between said power means and said drive shaft located approximately at the wall of said drum, said coupling being releasable to enable the drum to be removed from said tunnel member.

References Cited in the tile of this patent UNITED STATES PATENTS 1,227,093 Terhaar May 22, 1917 2,244,770 Englesson June l0, 1941 2,786,539 Nichols Mar. 26, 1957 FOREIGN PATENTS 281,638 Switzerland July l, 1952 

